1. Field of the Invention
The present invention relates to environmental seal means for connector assemblies and in particular to seal means used in connector assemblies that enhance a socket and plug insertion action.
2. Description of the Prior Art
In-line connectors, designed to function in a variety of environmental conditions, generally include annular space between the axially extending support surfaces about the input end of the plug and socket. To prevent moisture, dust, etc. from entering this annular space, some form of a seal or packing is inserted therebetween.
The seal or packing normally mounts over the extending support surface forming the inter-radius of the annular space. With the seal in place, a problem exists normally when inserting the plug into the socket. Usually the insertion force required to mate the plug and socket becomes unreasonable because some connector assemblies are multiple terminal devices. Each terminal in the assemblies creates an insertion force problem since each terminal contributes resistance to the insertion force needed to mate the plug to the socket.
In multiple terminal connector assemblies which are subject to various external forces such as continual vibrations, extreme temperature changes, excessive wind and rain, the terminals that are employed usually have a mating force of about 25 pounds or 40 ounces per terminal. If external locking mechanisms are employed to keep the plug mated to the socket, the mating force increases by, e.g., 3 pounds or 48 ounces, which represents the force needed to operate the lock mechanism.
Where the mating force of a connector is limited to a maximum of 30 pounds and there is a requirement, illustratively, for ten terminals per connector having a mating force of 40 ounces per terminal, and the connector assembly must be environmentally sealed, a search was initiated for an environmental seal scheme that would contribute a minimum mating force.
The prior art contains environmental seals for use in the annular space between the axially extending support surfaces of sockets and plugs of environmentally sealed connector assemblies.
Some forms of environmental seals have ribs or flanges that fold over onto the shaft of the seal and on or against adjacent ribs. Other seals have ribs that merely fold over onto the shaft of the seal but are compressed between the two extending support surfaces of the plug and socket respectively.
Such seals that fold as well as compress usually require the need for a relatively high insertion force for mating the plug and socket. A similar result occurs when the ribs of the seal overlap.
These prior art sealing arrangements are unacceptable when mating forces must be kept to a minimum.